To prevent turbulence and resonance, in an arrangement for application of liquids such as in an inking unit for a printing press with a liquid supply above the gap formed between a wiping roller and an applicator roller interacting therewith, it is known to immerse a flexible blade along the length of the two rollers in such a way that it rests tangentially on the applicator roller with its immersed end dividing the liquid supply into two unequal partial quantities. Such an arrangement is shown generally in DE-AS No. 1,561,116. In coating units of this type, which can also be combined with a perfecting unit such as shown in DE-PS No. 3,248,232, turbulence and resonance likewise occur in the coating supply according to the construction of the two-roller varnishing unit and corresponding to the diameters in the application of aqueous dispersion coating at higher speeds. However, the development of irregular air occulsions leads to more or less foamed areas at the metering gap, with the result that streakiness is produced on the coating applicator roller in the circumferential direction. The consequence is non-uniform coating application, so that streaks are visible in the printing material. Since the flexible blade rests tangentially on a roller, the communication possibilities between the partial quantities are inadequate and the vibration damping is effected only on the surface. Therefore, it cannot be used to damp different varnish quantities as far as the metering gap and simultaneously prepare uniform coating quantities.
In further efforts to prevent turbulence and resonance, it is also known how to provide an inking unit such as shown in DE-GM No. 1,707,927, in which the liquid or ink comes into contact with only one roller at the transfer point with a partition dividing the ink fountain in the longitudinal direction which forms a specific communicating gap with the bottom of the ink fountain and along the fountain roller. Consequently the turbulence formation is restricted to the smaller ink quantity occurring directly at the roller, but no measures are being taken to prevent or damp the turbulence of this part of the liquid. It is, however, important to damp precisely this part of the liquid that is in direct contact with the roller.
Inking units of different types with side walls at right angles to the axis of the rollers, which can be placed against the ink fountain roller with an end surface adapted to the curvature of the ink fountain roller shell, are also already known. The side walls do not bear any relationship to measures relating to the varnishing difficulties described above. This likewise applies to damping units of comparable design, which are provided with plates at the ends of the two damping rollers for lateral sealing of the liquid supply such as described in U.S. Pat. No. 3,404,625.